This invention relates to underground tanks for storing motor fuel, such as gasoline and diesel fuel, and more particularly, to equipment for containing spillage and overfill of motor fuel from underground storage tanks.
Underground storage tanks are used at service stations to store different blends (octanes) of gasoline and diesel fuel for customer service pumps. Underground tanks are filled from tank trucks and trailers. Tank trucks often have four or more compartments to hold different blends of gasoline and diesel fuel for different underground tanks in the service station.
Leaky fill hoses and defective hose connections between the tank truck and underground tank can cause spillage of motor fuel into the ground. Spillage will also occur if the fill hose is removed from the underground tank before the hose is properly drained.
Another problem is that inattentive drivers often overfill underground gasoline and diesel tanks. Such overfill will typically back up into the fill hose. When the driver disconnects and removes the fill hose, much of this excess motor fuel will spread over the driveway and drain into the ground.
Excess amounts of spillage and overfill of motor fuel might contaminate the soil and pollute groundwater and surrounding areas as well as create a fire hazard.
In recent years, many states, such as Florida and Michigan, have enacted containment laws and regulations to protect the environmental quality of the land and surrounding areas about which these underground storage tanks are located. Such containment laws and regulations generally require operators and owners of underground gasoline and diesel fuel tanks to provide means for containing spillage and/or overfill of the motor fuel.
Over the years, a number of devices have been suggested for containing petroleum and other materials. Typifying these prior art devices are those found in U.S. Pat. Nos. 3,732,902, 4,204,564, and 4,457,349. These prior art devices have met with varying degrees of success.
It is, therefore, desirable to provide an improved device which overcomes most, if not all, of the above problems.